Rubus hybrid.
xe2x80x98Chesapeakexe2x80x99.
This invention concerns a new and distinct cultivar of thorny blackberry plant with a botanical name of Rubus argutusxc3x97R. cuneifolius L. 
Several cultivars of thorny blackberry plants are known. xe2x80x98Chesapeakexe2x80x99 may be distinguished from its parent, xe2x80x98Shawneexe2x80x99 (U.S. Plant Pat. No. 5,686) and other large fruited thorny blackberry cultivars such as xe2x80x98Kiowaxe2x80x99 (U.S. Plant Pat. No. 9,861) by the recurvature of its spines and flavor of its fruit. It may be distinguished from xe2x80x98Black Buttexe2x80x99 (unpatented) by the type of spines and its erectness, compared to the semi trailing habit of the large fruited xe2x80x98Black Buttexe2x80x99. Fruit size and flavor distinguishes xe2x80x98Chesapeakexe2x80x99 from all other thorny blackberry cultivars known to us, including xe2x80x98Choctawxe2x80x99 (U.S. Plant Pat. No. 6,678), xe2x80x98Illini Hardyxe2x80x99 (U.S. Plant Pat. No. 8,333), xe2x80x98Ravenxe2x80x99 (unpatented) and xe2x80x98Rangerxe2x80x99 (unpatented). The presence of thorns and the size of the fruit distinguish xe2x80x98Chesapeakexe2x80x99 from thornless cultivars such as xe2x80x98Arapahoxe2x80x99 (U.S. Plant Pat. No. 8,510), xe2x80x98Navahoxe2x80x99 (U.S. Plant Pat. No. 6,679), xe2x80x98Hull Thornlessxe2x80x99 (unpatented), xe2x80x98Triple Crownxe2x80x99 (unpatented) and xe2x80x98Chester Thornlessxe2x80x99 (unpatented).
The new cultivar of blackberry originated from a controlled cross at the University of Maryland Greenhouses in College Park, Md. The cross xe2x80x9cSKNAxe2x80x9d was xe2x80x98Shawneexe2x80x99 (U.S. Plant Pat. No 5,686)xc3x97R. cunefolius (a wild selection from the town of Crisfeld, Md). This year was designated xe2x80x9cNxe2x80x9d as part of the University of Maryland at College Park; Rutgers University of New Brunswick, N.J.; Virginia Polytechnic Institute and State University, Southern Piedmont Agricultural Research and Education Center at Blackstone; and the University of Wisconsin at River Falls cooperative breeding program. The clone was first selected in 1992 at the Wye Research and Education Center of the University of Maryland located at Centerville, Md. and was therefore designated xe2x80x9cxe2x88x921xe2x80x9d. Thus, the complete breeding designation was xe2x80x9cNSKNA-1xe2x80x9d.
This application relates to a new and distinct thorny, spring bearing blackberry cultivar, botanically known as Rubus argutusxc3x97R. cuneifolius L. The following characteristics are outstanding:
1. Production of fruit which is much larger than the standard cultivars in use and larger or of equal size to two new extra large cultivars, xe2x80x98Black Buttexe2x80x99 (unpatented) and xe2x80x98Kiowaxe2x80x99 (U.S. Plant Pat. No. 9,861).
2. When compared to all othern eastern blackberry cultivars known to us, xe2x80x98Chesapeakexe2x80x99 has production of fruit which have a flavor less acid when slightly immature, at the glossy black fruit stage, allowing a slight blueberry flavor to emerge.
The following characteristics are useful in distinguishing this cultivar and can be useful for cultivar identification.
1. Plants are sparingly suckering and very upright, growing to 12 feet or taller when mature. Canes are only moderately cold hardy, i.e. not recommended for areas where the minimum winter temperature is less than 0xc2x0 F.
2. Canes, petioles, petiolules and leaf midribs have only a moderate amount of large recurved thorns.
3. The fruit is very large, typically 15-22 grams in the first picking and has an aroma of a blueberry in cooler temperatures. The flavor contains undetectable quantities of highly aromatic compounds typical of eastern U.S. erect thorny or semierect thornless blackberry cultivars.
4. The fruit is produced in the midseason from floricanes. Primocane produced fruit is unknown.